Dam safety compliance

Massachusetts dam safety requirements

MassDEP Office of Dam Safety (302 CMR 10.00) — what a private owner actually has to do, and when.

Frequently asked questions

When is a Massachusetts dam's inspection report due?

Within 30 days of the required professional-engineer inspection — a triggered filing window, not a fixed calendar date. Under 302 CMR 10.00, that inspection itself is required every 2 years for High-hazard dams, every 5 for Significant, and every 10 for Low.

Why doesn't Dam-Smart show a next-due date for my Massachusetts dam yet?

Because no public Massachusetts source — including MassGIS's own Dams layer, the only public MA dam dataset available — publishes each dam's last inspection date. Without that anchor date, a 30-day filing window can't be computed reliably, so Dam-Smart shows no due date rather than a fabricated one. Look up your dam to see its record as published; this is a known, tracked gap, not a bug.

What happens if a Massachusetts dam owner misses this deadline?

MassDEP's Office of Dam Safety can assess a penalty of up to $5,000 for non-compliance — a one-time figure, rather than the per-day penalties some other states use.

How to self-inspect a small dam

Even without a computable filing deadline here yet, routine self-inspection still matters — it's the record an engineer or MassDEP will ask for after the fact. Dam-Smart's inspection tool walks through six checkpoints, the same order a formal engineer inspection follows:

  1. Crest — walk the full length of the crest, checking for cracking, settlement, or unusual vegetation.
  2. Upstream slope — check the upstream slope for erosion, slumping, or animal burrows.
  3. Downstream slope — check the downstream slope for seepage, wet areas, or sinkholes.
  4. Spillway — confirm the spillway is clear of debris and vegetation and free to pass flow.
  5. Outlet works / drains — check outlet works and drains for blockage, damage, or unusual flow.
  6. Instrumentation — read and record any installed instrumentation, such as piezometers or staff gauges, where present.

Sourced from 302 CMR 10.00 and MassDEP's own guidance. See Mass.gov: Dam Safety Inspection Requirements for the primary source. This page is informational, not legal advice — verify current requirements with MassDEP's Office of Dam Safety directly.

Compare filing deadlines in all eight states

Requirements for other states: Connecticut · Georgia · North Carolina · New York · Ohio · Pennsylvania · Wisconsin